Sack filling method and apparatus

ABSTRACT

A method and apparatus for filling sacks with a predetermined quantity of product. The apparatus comprises at least one mobile sack feed and filling unit which carries each sack along the process line and at the same time fills the product into it. In the method according to the invention, the empty sacks are fed at the same speed as the mobile filling unit before they are transferred to the mobile filling unit itself.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a method and an apparatus forfilling sacks.

[0002] The method and apparatus according to this invention are used inparticular for filling sacks with a powdery or granular product such asflour or a similar type of product.

[0003] In prior art machinery used for this purpose, the sacks arestepped through the different stages in the sack filling process instop-start fashion.

[0004] Thus, in prior art machinery, the sacks are loaded, filled andsealed at separate working stations, stopping at each station to allow aparticular operation to be carried out before moving on to the nextstation. For each sack, the process cycle includes a first stop toenable the sack to be placed on the feed line.

[0005] This is followed by another stop to allow the sack to be filledwith the granular product, after which the sack moves on to the sealingstation where it stops again so that it can be sealed.

[0006] Although modern sack filling machinery is capable of performingthese operations extremely quickly, the average operating speeds of themachines that adopt this type of process cycle tend to be rather low,and, as a result, the overall performance of the machinery is notentirely satisfactory.

SUMMARY OF THE INVENTION

[0007] Therefore, according to one aspect of it, the present inventionprovides a method for filling sacks with products of different kinds, inparticular, powdery or granular products, wherein the sacks are filledwhile they are being fed forward.

[0008] This means that the sack filling apparatus operates continuouslyand can achieve average speeds that are higher than those of prior artmachinery, thus improving the output and overall performance of sackfilling lines.

[0009] According to another aspect of it, the present invention providesa method for transferring sacks to sack feed means in a sack fillingapparatus, wherein the sacks are transferred to the feed means whilethey are being fed forward.

[0010] This means that the sack filling apparatus operates continuouslyand performs the step of transferring the sacks to the feed meanswithout stopping, thus achieving average speeds that are higher thanthose of prior art machinery and improving the output and overallperformance of sack filling lines.

[0011] Specifically, in the method according to the invention, the sacksare made to travel at the same speed as the feed means before they aretransferred to the feed means.

[0012] According to yet another aspect of it, the present inventionprovides a method for transferring sacks to sack sealing means in a sackfilling apparatus, where the sacks are transferred to the sealing meansby the feed means without stopping the feed means.

[0013] This has the advantage of avoiding the need to stop each sack atthe sealing station and of thus improving the productivity of theapparatus according to the invention.

[0014] The combination of the sack filling, transfer and outfeed steps,which are carried out continuously without stopping, also makes itpossible to provide an apparatus where the sacks are not stopped duringthe entire process cycle and whose productivity can be maximized whileat the same time reducing wear and minimizing the risk of breakingmachine parts due to excessive speeds to perform certain steps in theprocess.

[0015] Accordingly, the invention provides an advantageous apparatus forfilling sacks.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The technical characteristics and advantageous aspects of theinvention are apparent from the detailed description which follows, withreference to the accompanying drawings which illustrate a preferredembodiment of the invention provided merely by way of example withoutrestricting the scope of the inventive concept, and in which:

[0017]FIG. 1 is a top view of the preferred embodiment of an apparatusaccording to the present invention;

[0018]FIG. 2A is an elevation view of the sack filling section of thepreferred embodiment of the apparatus according to the presentinvention;

[0019]FIG. 2B is an elevation view of a part of the mounting frame ofthe apparatus according to the present invention;

[0020]FIG. 3 is a top view of a part of the preferred embodiment of theapparatus according to the present invention, showing the bottom of themobile frame mounting the units that fill the sacks as they move;

[0021]FIG. 4A is a top view of the upper part of the carousel and showsthe mobile product conveyor hoppers in the preferred embodiment of theapparatus according to the present invention;

[0022]FIG. 4B is an elevation view of the mobile hopper area;

[0023]FIGS. 5A and 5B are top views showing, in two different operatingconditions, the sack loading section of the apparatus where an emptysack is transferred to a mobile filling unit;

[0024]FIG. 6 is a front view showing only the unit that picks up thefull sacks from the carousel in the preferred embodiment of theapparatus according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The accompanying drawings illustrate a preferred embodiment 10 ofan apparatus according to the invention used to fill sacks with agranular or powdery product.

[0026] This apparatus advantageously enables the sacks to be filled asthey move, without having to stop each sack during the filling step orduring the other steps in the process, as is necessary in sack fillingmachines known up to now.

[0027] More specifically, in accordance with another advantageous aspectof the invention, the sacks are transferred to the means that feed themduring the filling step so that it is not necessary for the apparatus tostop to enable empty sacks to be loaded.

[0028] As shown in particular in FIGS. 1 and 2A, the preferredembodiment of the sack filling apparatus according to the inventionadvantageously comprises a plurality of mobile filling units, labeled 12a, 12 b, 12 c and 12 d in the drawings. These are rotatably mounted on aframe 14 in such a way as to form a carousel that preferably rotatescontinuously.

[0029] In the preferred embodiment of the invention, there are fourunits for feeding and filling the sacks 13. These units are positionedat angular intervals of 90° from each other in such a way that while oneof them is picking up an empty sack (in the working position shown inFIG. 2A, the unit 12 a), and another of them (in the working positionshown in FIG. 2A, the unit 12 d) is dispensing a full sack to asubsequent unit 16 that seals it and unloads it full from the machine,the other two (in the working position shown in FIG. 2A, the units 12 band 12 c) are filling their sacks.

[0030] As illustrated, the apparatus according to the inventionpreferably comprises four sack feeding and filling units. The apparatus,however, might also have a different number of sack feeding and fillingunits. In another preferred embodiment, for example, the apparatus mighthave six mobile sack feeding and filling units positioned at angularintervals of 60° from each other.

[0031] As shown in particular in FIG. 2A, each sack feeding and fillingunit comprises grippers which hold and support the sacks by theirlateral edges. In FIG. 1, the grippers are labeled 18 and, being of atype well-known to experts in the trade, are not described in detail.

[0032] The grippers 18 arrive at the sack receiving position in the openor jaws-apart condition and are closed over the upper portion of thesack when the sack is transferred to them by the loading means. Theloading means are described in more detail below.

[0033] The grippers 18, 18 catch hold of the sack at a level just abovethe where the sack is held by the loading means (described in moredetail below). Thus, the upper edge of the sack is held by the loadingmeans in a sufficiently vertical position to enable it to be easilypositioned between the opposing jaws of the grippers 18, 18 of themobile filling unit.

[0034] To engage and release the sack, the opposing jaws of the grippers18, 18 are turned about a vertical plane, actuated by appropriatepneumatic cylinders mounted on each mobile filling unit.

[0035] As shown in more detail in FIG. 2A, each sack feeding and fillingunit also comprises suction cups. These suction cups, labeled 20 in FIG.1 and also of a type well known to experts in the trade, engage theupper portions of opposite faces of the sack and adhere to them thanksto a suitable vacuum so that, when the suction cups are moved apart, theupper opening of the sack is opened.

[0036] As illustrated, the suction means for opening the sack arepositioned in such a way as to engage and open the opposite upper edgesof the sack extending between the grippers 18, 18, in the position shownby the dashed line in FIG. 2A, moving into the gap between the opposinggrippers 18 that are holding the opposite lateral edges of the sack.Once the sack has been opened, the suction means release the centralupper portion of the sack and move to the position shown by thecontinuous line in FIG. 2A.

[0037] The grippers 18 hold the sack while the suction cups 20 movetowards each other to engage the upper outer surface of the sack andthen move apart to allow the lower end of the filler pipe, labeled 22 inthe drawings, to be inserted into the sack. The filler pipe is notdescribed in any detail since it is also of a type well known to expertsin the trade.

[0038] To enable the opposite edges of the sack to be moved apart by thesuction cups so that the downwardly extending end of the filler pipe canbe inserted, the grippers 18, 18 slacken the upper portion of the sackby moving towards each other, actuated by pneumatic cylinders,preferably cylinders 18 a, 18 a, illustrated schematically in FIG. 1,extending lengthwise in the corresponding unit. In FIG. 1, pneumaticcylinders labeled 18 b, 18 b impart on the jaws of the grippers 18, 18the required gripping motion and preferably extend from a centralposition in the filling unit in a direction transversal to the unit.

[0039] As illustrated in the drawings, the sack filling suction meansare supported by an arm 23 which is pivotally mounted on a portion ofthe frame of the mobile unit and which is actuated by a pneumaticactuator 25 that moves it between a first angular raised position ofnon-interference with the other parts of the apparatus, to the loweredangular positions mentioned above where the opposite edges of the sackare first engaged and then moved apart to permit insertion of the fillerpipe.

[0040] In FIG. 2A, the numeral 27 denotes a pneumatic actuator used toopen and close the filler pipe.

[0041] Once the sack has been filled, the grippers 18, 18 release thefull sack and transfer it to the next unit 16 (shown also in FIG. 6),which, at the sack receiving zone, is equipped with a pair of opposingbelts 24, 24, which—when at the sack receiving end are moved relative toeach other between a position where they are apart so that they canreceive the sack and a position where they are close together so thatthey can engage and grip the sack.

[0042] Looking in more detail, this sack gripping movement is impartedby a pneumatic actuator 29, which engages a lever 31′ attached to asupporting portion 24′ of the end of one of the belts 24, the portion24′ being pivotally mounted at 24″ (see FIG. 6) to the frame of theapparatus in such a way as to swing the end of the belt 24 in asubstantially horizontal plane so that it can receive and grip the sack,as shown in FIG. 6.

[0043] Once the belts 24, 24 have caught hold of a sack, they feed itdownstream in a straight line, as described in more detail below.

[0044] After transferring the full sack to the section 16, the grippers18, 18 remain in the open or jaws-apart condition until they reach theempty sack loading zone.

[0045] The mobile mounting frame 14 comprises an upper portion 14 awhich, for each filling unit, mounts the sack grippers 18, 18, the sackopening suction means 20, 20 and the pipe 22 that fills the product intothe sack.

[0046] The upper portion 14 a of the mounting frame of the sack feed andfilling units also mounts, at the top of the sack feed and filling zone,a hopper 26 for each of filling units 12 a, 12 b, 12 c, 12 d.

[0047] As better illustrated in FIGS. 4A and 4B, each of the hoppers 26comprises a main hopper body which, in the direction of feed, presentsan asymmetrical shape.

[0048] The body of each hopper 26 presents a longitudinal front wall28′, a longitudinal rear wall 28 opposite it, and side walls 28 a, 28 bconverging downwardly towards a lower opening 30 that dispenses productto the filler pipe 22 below.

[0049] Looking in more detail, the rear hopper wall 28 makes a sharperangle with the horizontal than the wall 28′ opposite it so as to form alarge opening at the top of the hopper. More specifically, the upperopening of the hopper, formed by the upper profile 32′ of the hopperitself, extends circumferentially backwards starting from a verticalposition corresponding substantially to the lower opening 30, in such away as to discharge a sufficient quantity of product to completely fillthe sack.

[0050] Indeed, the product to be filled into the sacks is dispensed tothe hopper 26 through a hole, which is not illustrated in the drawings,made in the fixed top cover plate T′ of the apparatus and the angularlength of the upper opening of the hopper is such as to enable therequire quantity of product to be discharged as the hopper itself movesforward.

[0051] As illustrated in particular in FIGS. 2A and 3, the rotatingframe comprises, in addition to the upper section 14 a, a lower section14 b, which rotates together with the upper section 14 a and which isadjustably mounted for height relative to the latter so that theapparatus can be adapted to different sack sizes.

[0052] The lower frame 14 b mounts, for each mobile filling unit, alower board 34 to support the sack 13, the board 34 being mounted on apair of L-shaped brackets 36 which are connected to the lower framesection 14 b in such a way that they rotate in a vertical plane andwhich are actuated by pneumatic cylinders 38.

[0053] The rods 40 of the cylinders 38 engage an extension 42 of eachbracket 36 in such a way as to move the board 34 between a horizontal orraised position in which it supports the sack and a lowered or retractedposition which enables the rotating apparatus to turn freely withoutinterfering with other components, especially with the conveyor belt 25of the sack outfeed unit shown in FIG. 6.

[0054] The sack supporting board includes an element or strip, labeled44 in FIG. 1, designed to stop the bottom of the sack and alternatelydriven by pneumatic cylinders 46 in such a way that it repeatedlystrikes the bottom of the sack in order to distribute the product evenlywithin the sack.

[0055] The raising of the lower section of the rotating apparatus isadvantageously accomplished by a motor, labeled 48 in FIG. 1, thatdrives an appropriate rack, which is not illustrated, connected to thelower frame section 14 b.

[0056] Another electric motor rotates the entire frame 14 and thefilling units mounted on the frame 14. This drive motor is notillustrated in FIG. 2A.

[0057] The drive transmission mechanisms enabling the rotation andrelative vertical motion between the upper and lower sections are wellknown to experts in the trade and are housed within a central zonecovered by a concertinaed tubular element 49 made of a flexible materialwhich opens and closes axially in multiple folds in such a way as tofollow the movements of the lower section 14 b.

[0058] As shown in particular in FIG. 2B, the means for supporting theapparatus according to the invention comprise a fixed frame I includinga trestle with columns C (viewed from above in FIG. 1), that support afirst quadrangular beam T and a second top cover plate T′.

[0059] As can be seen in particular in FIGS. 2A and 2B, the mobileapparatus comprises a circular plate 14′, which supports the uppersections of the mobile units, that is to say, the grippers 18, 18, thesuction means, the filler pipes 22 extending downwardly from thecircular plate, and the hoppers 26 extending upwardly from the circularplate. The circular plate 14′ is perforated at the openings throughwhich the product passes from the hoppers 26 to the underlying fillerpipes 22.

[0060] In addition, the apparatus mounting means comprise a lower fixedbase B, illustrated in FIG. 2A, to which the lower frame section 14 b isconnected in freely rotatable fashion.

[0061] In particular, as can be seen also in FIG. 3, the lower mobileframe section 14 b comprises a central shaft 14′b and a plurality ofradial arms 14″b that support the lower sections of the mobile fillingunits 12 a, 12 b, 12 c, 12 d.

[0062] The plate 14′ is rotatably mounted on the trestle by appropriatemeans extending from the central plate and slidably engaging with thequadrangular beam T.

[0063] Means for guiding the circular motion of the frame 14 areincluded. As shown in FIG. 2B, the means for guiding the circular motionof the frame 14 comprise a circular surface 141, which is defined by atubular portion centrally positioned on the top cover plate T′ and whichcontacts the outer surface 143 of a central supporting column 145 of thecircular plate 14′.

[0064] Further, as illustrated in FIG. 2A, the means for guiding thecircular motion of the frame 14 comprise a vertical rod 142 extendingdownwardly from the central shaft 14′b that mounts the bottom section 14b of the fixed frame.

[0065] As shown in FIGS. 5A and 5B, the means 50 for transferring thesack to a corresponding sack feed and filling unit comprise grippermeans designed to hold the sack and being equipped with elongatedopposing jaws 52, 52 actuated by pneumatic cylinders 53 mounted on aframe 54.

[0066] The frame 54 moves along a linear path which, at the zone wherethe sack is transferred to the sack feed and filling unit—illustrated bythe dashed line in FIG. 5B, labeled 12 in its entirety—is substantiallytangent to the circular path followed by the filling unit 12.

[0067] With reference to FIGS. 5A and 5B, the sack pickup and transfermeans 52, 52 are driven by a pneumatic cylinder 55 from a retractedposition (shown in FIG. 5A) where the sack is received fromcorresponding lifting means, described in more detail below, to anadvanced position (shown in FIG. 5B) where the sack is transferred to acorresponding mobile filling unit 12.

[0068] During this linear movement, the frame 54 and the gripper 52, 52mounted on it, are accelerated until they reach the same tangentialspeed as the sack grippers 18, 18 of the mobile rotating sack fillingunits.

[0069] By the time the grippers 52, 52 holding the top of the sack havereached the same speed as the mobile filling units, the upper edge ofthe sack is between the open grippers 18, 18 of the mobile filling unit,as illustrated in FIG. 5B. At this point, the grippers 18, 18 close andthe gripper 52, 52 of the transfer or linear acceleration unit open torelease the empty sack to the corresponding mobile filling unit.

[0070] To enable this linear movement, the frame 54 has an offset part54 a which projects from the part 54 b that mounts the gripper 52, 52towards the zone of the rotating carousel that mounts the mobile fillingunit's. This mounting part 54 a of the frame 54 slides through bushes 58on a pair of guide rods 56, the latter being fixed to the machine frame,which also has fixed to it, through the plate 57, the cylinder 55, thefree end of whose mobile rod 55′ is connected to the part 54 a of thelinearly mobile frame 54.

[0071] As illustrated, this part 54 a is attached to a pair of bushes 58enabling it to slide on the fixed guide rods 56, which have a circularcross section and on which another two bushes 58, 58 slide axially, thelatter being attached to the front part of the portion 54 b of themobile frame 54.

[0072]FIG. 5A illustrates a step in which the empty sack lifting means,labeled 60 in their entirety, transfer the sack to the linearly mobilegripping means 52, 52.

[0073] The empty sack lifting means 60 pick up the empty sack at the endof the conveyor belt 61 (clearly shown in FIG. 1), on which the emptysacks are lined up, and comprise a pair of grippers (labeled 62, 62 inFIG. 5A and actuated by respective pneumatic cylinders 63′, 63′), eachmounted on an arm 64, 64 which is rotatably connected to the machine ata point above the end of the conveyor belt 61 where the sack is pickedup.

[0074] The arms 64, 64 are driven by a corresponding pneumatic cylinderwhich makes them perform an angular rotation in a vertical plane betweena lowered position where the arms 64, 64 extend downwards vertically andthe grippers 62, 62 grip the sides of the sack to pick it up from theconveyor 61, and a raised position where the arms 64, 64 aresubstantially horizontal and the grippers 62, 62 are ready to open, asillustrated in FIG. 5A, to transfer the sack to the gripper 52, 52 aboveit which is designed to accelerate the sack tangentially. The step oflifting the sack is not illustrated in detail in the accompanyingdrawings.

[0075] To perform this sack transfer operation easily, the grippers 62,62 of the lifting unit 60 grip the sack at a zone below the zone wherethe sack is gripped by the tangential acceleration gripper 52, 52.

[0076] When the lifting means 60 are in the raised position, the upperedge of the sack is inserted between the jaws 52, 52 of the linearacceleration unit 50, as illustrated in FIG. 5A. After releasing thesack 13, they return to the lowered position to pick up the next sackfrom the feed belt 61.

[0077] In FIG. 5A the numerals 63′, 63′ denote pneumatic cylindersmounted on the arms 64, 64 and designed to open and close the grippers62, 62.

[0078] With reference to FIGS. 1 and 6, the downstream unit 16 forsealing the sack and feeding it out of the machine extends on one sideof the filling unit, where the carousel 14 operates, and on one side ofthe empty sack feed belt 61. The sack sealing and outfeed unit 16comprises pair of opposing belts 24, 24, extending in a straight line,which transfer the full sack along a defined linear path between thesack sealing stations, illustrated schematically in FIG. 1, and feed thesealed sack out from the end opposite end where the full sack isreceived from the carousel.

[0079] These straight, opposing belts 24, 24 are positioned above aconveyor belt, labeled 25 in FIG. 6, which supports the bottom of thesack 13. The conveyor 25 extends horizontally parallel with the belts 24and supports longitudinal rods 27, which engage the outer profile of thesacks forming lateral guide means for the sacks themselves.

[0080] As shown schematically in FIG. 1, the sack sealing operation isperformed by a station 63 that trims or cuts the upper edge of the sack,a station 65, immediately downstream of it, that applies glue to theupper edge of the sack, a first folding station 67 that brings thisedge, with glue applied to it, into contact with an underlying outsidesurface of the upper portion of the sack so that it adheres, and asecond folding station 69 that enables the sack to be sealed. Theseoperations are performed with the sack orientated sideways in thedirection of feed and moving in a straight line without stopping towardsthe outfeed station.

[0081] The full sack might also be sealed by stitching or heat sealing.

[0082] As illustrated in FIG. 1, the present sack filling and sealingmachine essentially comprises a magazine 8 designed to house a pluralityof piles of empty sacks to be fed into the machine, a section 9,downstream of this magazine, which aligns the sacks on the conveyor belt61, which extends parallel to the sack outfeed and top sealing line 16,and which carries the sacks towards an end pickup position where a sacklifting unit 60 transfers them to the unit 50 that feeds them to therotating sack filling carousel.

[0083] As illustrated in the drawings, the present apparatus has asubstantially L-shaped configuration having the advantage of beingextremely compact and easy for personnel to access in the event of afault, when the machine has to be reset and restarted, or for thepurposes of maintenance and repairs.

[0084] In the filling apparatus described above, the sacks follow anangular path through approximately 270°. Thus, the total distance theytravel is short and the duration of the filling process cycle is reducedto a minimum. Although the angular path through 270° is preferable, adifferent angular path through a different angle (greater or less than270°) is also possible.

[0085] Moreover, the sacks are filled within an angular interval thatdoes not exceed 90°. Thus, the sack is easily filled without impartingexcessive centrifugal forces which might hamper filling operations.

[0086] In the present apparatus, the sacks are transferred to the sacksealing means 16 by the feed and filling means 12 without stopping thefeed means 12 themselves. More specifically, as the sacks aretransferred to the sealing means 16 by the feed means 12 they move in asubstantially linear direction tangent to the circular path along whichthe sacks themselves were previously fed by the feed means 12.

[0087] To transfer a full sack to the belts 24, 24 of the sack topsealing unit 16, the sack gripping means 18, 18, of the correspondingmobile unit 12 release the upper edge of the sack sequentially as theupper edge reaches the belts. In practice, the gripper 18 that is at thefront, in the angular direction of feed, is opened to release the sackbefore the opposite gripper 18, which, in said direction of feed, isbehind it. Thus, the front gripper 18, which is the first to reach thebelts 24, 24, releases the upper edge of the sack as soon as it ispicked up by the belts. The other gripper 18, which next reaches thebelts, releases the sack as soon as it arrives at the front end of thebelts, which, in the meantime, have fed the front portion of the sackforward, as can be seen in FIG. 6.

[0088] It should be noticed that at the linear acceleration means of thesacks, the sack gripper 52, 52 and the cylinder that drives it in astraight line, might be substituted by a pair of opposing belts to holdthe sacks and feed them in a straight line, such belts being equippedwith means to move them together in such a way that they catch hold ofthe sacks, as well as means to move them apart in such a way that theyrelease the sacks and transfer them to the unit downstream.

[0089] Feed belts of this type might also be used at any other point inthe apparatus where required or convenient.

[0090] It will be understood that the invention can be subject tomodifications and variations without thereby departing from the scope ofthe inventive concept. Moreover, all the details of the invention may besubstituted by technically equivalent elements.

What is claimed is:
 1. A method for filling sacks with products ofdifferent kinds, in particular, powdery or granular products, whereinthe sacks are filled while they are being fed forward.
 2. A method fortransferring sacks to sack feed means in a sack filling apparatus,wherein the sacks are transferred to the feed means while they are beingfed forward.
 3. The method according to claim 2, wherein the sacks aremade to travel at the same speed as the feed means before they aretransferred to the feed means.
 4. The method according to any of theforegoing claims, wherein the sack feed means follow a circular feedpath.
 5. The method according to any of the foregoing claims, whereinthe means for transferring the sacks to the feed and filling meansfollow a linear path which, at the zone where the sack is transferred,is substantially tangent to the circular path followed by the feedmeans; the transfer means, when they are at the sack transfer zone,traveling at the same tangential speed as the feed and filling means. 6.The method according to any of the foregoing claims, wherein the sacksfollow an angular path through approximately 270°.
 7. The methodaccording to any of the foregoing claims, wherein the sacks are filledwithin an angular interval that does not exceed 90°
 8. A method fortransferring sacks to sack sealing means in a sack filling apparatus,wherein the sacks are transferred to the sealing means by the feed andfilling means without stopping the feed and filling means.
 9. The methodaccording to claim 8, wherein, as the sacks are transferred to thesealing means by the feed means, they move in a substantially lineardirection tangent to the circular path along which the sacks themselveswere previously fed by the feed and filling means.
 10. The methodaccording to any of the foregoing claims, wherein the sacks are fedforward on means that support them at an adjustable height.
 11. Anapparatus for filling sacks with a predetermined quantity of product,especially a granular or powdery product, the apparatus being equippedwith means for feeding the sacks, means for transferring the sacks tothe feed means and means for filling the sacks, the apparatus comprisingat least one mobile unit for feeding and filling a corresponding sack,the mobile unit comprising means that support means for gripping andholding the sack and means for filling the sack; means also beingprovided to feed the mobile unit along a defined path.
 12. The apparatusaccording to claim 11, comprising a plurality of mobile units forfeeding and filling the sacks.
 13. The apparatus according to claim 11or 12, wherein the mobile units for feeding and filling the sacks followa circular feed path.
 14. The apparatus according to any of theforegoing claims from 11 to 13 or according to the preamble to claim 11,wherein the means for transferring the sacks comprise means whichsupport means for gripping and releasing the sacks, said support meansbeing driven at the same speed as the mobile feed and filling units toenable the sack to be transferred to the corresponding feed and fillingunit itself.
 15. The apparatus according to any of the foregoing claimsfrom 11 to 14, wherein the means for transferring the empty sack to oneof the mobile feed and filling units follow a path that presents atleast one section extending in a direction substantially tangent to thepath followed by the sack holding means of the mobile filling unit. 16.The apparatus according to any of the foregoing claims from 11 to 15,wherein the mobile units for feeding and filling the sacks are mountedon a rotating mounting frame.
 17. The apparatus according to any of theforegoing claims from 11 to 16, wherein the filling means on the mobileunit comprise a filler pipe which discharges the product into the sack.18. The apparatus according to any of the foregoing claims from 11 to17, wherein each mobile feed and filling unit comprises means forsupporting the bottom of the sack, said means being adjustably mountedfor height so as to adapt to sacks of different sizes or heights. 19.The apparatus according to any of the foregoing claims from 11 to 18,wherein each mobile feed and filling unit comprises means for stoppingthe bottom of the sack, said means being adjustably mounted for heightso as to adapt to sacks of different sizes or heights.
 20. The apparatusaccording to any of the foregoing claims from 11 to 19, wherein themounting frame of the mobile feeding and filling units comprises arotatable, vertically fixed upper section and a lower section that canbe adjusted in height relative to the upper section and that isoperatively connected to, and rotatable with, the latter, the means forsupporting the bottoms of the sacks and/or the means for stopping thebottoms of the sacks being mounted on the frame lower section.
 21. Theapparatus according to any of the foregoing claims from 11 to 20,wherein the mobile filling unit comprises at least one upper hopper thatmoves together with the mobile filling unit and has a lower opening fordischarging the product into a corresponding filler pipe and an upperopening for receiving the product.
 22. The apparatus according to claim21, wherein the upper opening in the hopper communicates with a holemade in a fixed upper flange and is elongated in the direction oppositethe feed direction so that a sufficient quantity of product tocompletely fill the sack can be discharged into the hopper.
 23. Theapparatus according to any of the foregoing claims from 11 to 22,wherein each mobile feed and filling unit comprises suction means foropening the top of the sack.
 24. The apparatus according to any of theforegoing claims from 11 to 23, or according to the preamble to claim11, further comprising a longitudinal section that extends along oneside of the filling section and that is designed to seal the top of thesack and feed the sack out of the apparatus.
 25. The apparatus accordingto claim 24, wherein the sacks are transferred to the sealing means bythe feed and filling means without stopping the feed and filling means.26. The apparatus according to claim 24 or 25, wherein, as the sacks aretransferred to the sealing means by the feed and filling means, theymove in a substantially linear direction tangent to the circular pathalong which the sacks themselves were previously fed by the feed andfilling means.
 27. The apparatus according to any of the foregoingclaims from 11 to 26, wherein the apparatus mounting means comprise afixed frame that rotatably mounts the frame which mounts the mobilefilling units.
 28. The apparatus according to any of the foregoingclaims from 11 to 27, wherein the lower mobile frame section comprises acentral shaft and a plurality of radial arms that support the lowersections of the mobile filling units.
 29. The apparatus according to anyof the foregoing claims from 11 to 28, further comprising means forguiding the circular motion of the frame.
 30. The apparatus according toclaim 29, wherein the means for guiding the circular motion of the framecomprise a circular surface which slidably engages an outside surface ofa central column that mounts a plate which supports the mobile feed andfilling units.
 31. The apparatus according to any of the foregoingclaims from 11 to 31, wherein the means for guiding the circular motionof the frame comprise a vertical rod extending downwardly from thecentral shaft that mounts the bottom section of the mobile frame. 32.The apparatus according to any of the foregoing claims from 11 to 31,wherein, seen from above, the apparatus has a substantially L-shapedconfiguration.
 33. The apparatus according to any of the foregoingclaims from 11 to 32, wherein, to transfer the full sack to the sacksealing means, the sack gripping means of the corresponding mobile unitrelease the upper edge of the sack sequentially as they reach the sackreceiving means of the sealing means.